Editing Gee (navigation) (section)

{{Short description|Radio navigation system}}
{{Use dmy dates|date=November 2014}}
[[File:J M Briscoe24 07 200713 05 14IMG2104 GEE AIRBORNE.JPG|thumb|GEE airborne equipment, with the R1355 receiver on the left and the Indicator Unit Type 62A on the right. The 'scope shows a simulated display, including the "ghost" A1 signal.]]
[[File:J M Briscoe24 07 200713 09 22IMG2114 GEE CONTROL.JPG|thumb|right|GEE control bays]]
[[File:J M Briscoe24 07 200713 08 57IMG2113 GEE TX.JPG|thumb|right|GEE transmitter]]

'''Gee''', sometimes written '''GEE''',{{efn|Different sources record the name as GEE or Gee. The naming supposedly comes from "Grid". "Gee" is used in Dippy's publications. See Dippy 1946. The Air Ministry sometimes referred to it as Gee-7000.  or '''Gee-7000''', see [http://www.vmarsmanuals.co.uk/archive/632_AP1093D_Pt2_Introductory_Survey_of_Radar_screenread.pdf "An Introduction Survey of Radar, Part II"], Air Ministry, June 1946}} was a [[radio-navigation]] system used by the [[Royal Air Force]] during [[World War II]]. It measured the time delay between two radio signals to produce a [[Fix (position)|fix]], with accuracy on the order of a few hundred metres at ranges up to about {{convert|350|mi|km}}. It was the first [[hyperbolic navigation]] system to be used operationally, entering service with [[RAF Bomber Command]] in 1942.

Gee was devised by Robert Dippy as a short-range [[Instrument approach|blind-landing]] system to improve safety during night operations. In the course of development by the [[Telecommunications Research Establishment]] (TRE) at [[Swanage]], the range was found to be far better than expected. It then developed into a long-range, general navigation system. For large, fixed targets, such as cities that were attacked at night, Gee offered enough accuracy to be used as an aiming reference without the need to use a [[bombsight]] or other external references. [[Radar jamming and deception|Jamming]] reduced its usefulness as a bombing aid, but it remained in use as a navigational aid in the UK area throughout and after the war.

Gee remained an important part of the RAF's suite of navigation systems in the postwar era, and was included in aircraft such as the [[English Electric Canberra]] and the [[V-bomber]] fleet. It also had civilian use, and several new Gee chains were set up to support military and civil aviation across Europe. The system started to be shut down in the late 1960s, with the last station going off the air in 1970. Gee inspired the original [[LORAN]] ("Loran-A") system.